Earlier research on emotional signaling processes in infancy will be extended with studies in the second and third years of life. A set of limited longitudinal studies will bracket the developmental shifts involving the onset of walking and the onset of the two- word phase of language acquisition. In an age-held-constant design for each shift, both the changing emotional signals of the infant and the mother's emotional availability will be considered as dependent variables. a related set of studies involves indicators of another developmental shift, namely, that of the child's moral internalization during the third year. Ongoing investigations will be completed including: 1) a family longitudinal study of emotional signaling with firstborns aged 6 through 36 months and 2) experimental social referencing studies in the post- walking 1-year-old. An additional set of studies involves collaborative interdisciplinary research in emotional signaling. Both studies will assess consistency and change in the child's behavior. One study consists of the collection of videotaped database for cross- situation, cross-person comparisons of emotional signaling between toddlers and mothers and between toddlers and familiar peers. Data are collected during three separate home visits at 18 and 24 months of age, and there is a laboratory assessment session at 38 months. Another study uses a behavioral genetics approach for assessing continuities and change in emotionality. A longitudinal twin study will make repeated home and laboratory observations at age points from 14 through 36 months. Measures from our laboratory of emotional signaling will be combined with measures from other laboratories involving cognitive, temperament and empathy measurements.